Câu hỏi

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase for each of the blanks. A long time ago, when ancient Rome was still an empire, people of that time used similar weights and measures. The standards for these weights and measures were established by the Romans, who kept these standards in a temple in Rome. All standards for measuring weight or distance were the same, whether in Spain or in Syria. But then the Roman Empire fell, and these standards disappeared. Today, standards vary from place to place throughout the world. Tourists who drive from the United States in Canada, for example, are surprised when they buy gasoline for their cars. A gallon of gas costs more than they are accustomed to paying. They complain that prices are much higher in Canada than in the United States. Then they discover that they can drive farther on a Canadian gallon than on a United States gallon. Is it a different kind of gas? No, it is a different kind of gallon. Canada uses the British, or imperial, gallon that is about one-fifth larger than the United States gallon. Four quarts equal a gallon and two pints equal a quart in both countries. But Canada‟s quarts and pints are larger than quarts and pints in the United States. The imperial gallon equals 277.42 cubic inches while the gallon in the United States is equal to 231 cubic inches. Measured in ounces, Canada‟s large gallon holds 160 fluid ounces, while the smaller United States gallon holds no more than 128 fluid ounces. From these figures, it is easy to see why Americans can drive farther on the Canadian gallon than on the American gallon. Someday, countries may follow the example of the ancient Romans and make weights and measures the same for every nation. The word empire in the first line refers to_________.